Sound absorbing unit and bundle thereof



Aug. 4, 1959 BARSHEFSKY 2,897,908

SOUND ABSORBING UNIT AND BUNDLE THEREOF Filed 00"). 4, 1956 UnitedStates Patent SOUND ABSORBING UNIT AND BUNDLE THEREOF GustaveBarshefsky, Chicago, Ill., assignor to The Celotex Corporation, Chicago,Ill., a corporation of Delaware Application October 4, 1956, Serial No.613,935

2 Claims. (Cl. 181-33) The invention hereof is with respect to a new andnovel sound absorbing unit constructed in a novel manner and is withrespect to a most novel manner of packaging such units.

The unit hereof is of such construction that it is extremely light inweight so that the shipment of such units in the normal manner is to allintents and purposes prohibitive in cost due to the fact that a truckload or freight carload would Weigh but a relatively few pounds.

The unit hereof is so constructed that for shipment it may be so bundledor packaged that the volume thereof when prepared for shipment isappreciably decreased as compared with the usual volume of the unit, andconsequently shipping costs can be materially reduced.

The sound absorbing unit hereof is of the type sometimes referred to asan acoustic sink, a functional sound absorber, or, in some cases, assound absorbing baflles. These unitsare ordinarily installedindividually, that is, each unit is usually independently mounted orsuspended spaced from other such units comprising the over-allinstallation. Of course, at times they may be mounted in individualrows, that is, in spaced rows but with the ends of the units in orsubstantially in contact. This particular unit, as mentioned, is adaptedto be suspended from a ceiling or overhead supporting member, but it isimmaterial whether it is mounted in any particular manner.

The unit may be suspended from suitable supporting members eitherhorizontally or vertically with its faces parallel to the floor orceiling, or angularly or diagonally with respect thereto. The unit mayeven be suspended from one corner or in some areas the unit may be, forexample, suspended of its lengthwise axis running in one direction andin another area with its axis running in a different direction.

The unit as herein particularly disclosed and described comprises asheet metal casing and suitable sound absorbing material in combination.It is to be understood, however, that the specific showing anddescription is not by way of limitation, and that the casing instead ofbeing of metal may be of carboard-like material, or substantially anysheet material which may be folded. The invention comprehends thecombination of such casing and sound absorbing filler which is of unitform and combined with the casing in a specific manner. Here again,however, while the preferred material, and that which will bespecifically referred to herein, is a very light weight glass woolblock, it is to be understood that other equivalent light weight soundabsorbing materials may be substituted therefor, as, for example, lightweight resilient plastic foam having the requisite light weight andsound absorbing property, or light weight elements comprised of otherfibrous materials so felted or constructed as to be of light weight andhaving the requisite sound absorption.

The procedures for the packaging or bundling of these units for economicshipment and handling will not be referred to at this point other thanmost generally. The otherwise fabricated but not formed units arecompacted ice for shipment by stacking a plurality thereof followed bycompression of the stack to a higher unit density, whereupon the suchcompressed stack is suitably banded or the like to retain it in suchcompressed state. In such compressed state the individual units are muchsafer against damage in shipment and, particularly, due to the increaseddensity, the units may be shipped much more economically than can be thecompleted or formed but uncompressed units.

The particular objects of the invention hereof are the provision of afunctional type sound absorber unit which is simple to make, which hasvery low-unit weight, high absorption and the like, and is economical tomanufacture.

A further object of the invention is the provision of a bundle orpackage of functional type sound absorber elements where, bycompression, the density has been appreciably increased with theconsequence that there results considerable economy in the shipment andhandling, and particularly whereby the units so bundled or packaged areless susceptible to damage in shipment.

In the accompanying drawings, wherein exemplifications of the inventionsare illustrated, Figure 1 is a perspective of a functional soundabsorber hereof;

Figure 2 is a top plan view of the unit as it is manufactured beforeformation into the finished unit;

Figure 3 is an end elevation of the unit of Figure 2;

Figure 4 is a diagrammatic illustration showing the manner in which twoof the units, as manufactured, may be nested;

Figure 5 is a diagrammatic showing of two of the units actually nested;

Figure 6 is a diagrammatic illustration of two such nested units whichhave been somewhat compressed; and

Figure 7 is a diagrammatic showing of the bundle or bale of units asprepared for shipment.

In the drawings the complete fabricated unit is identified by thenumeral 10, such being shown with suspending wires or straps 11 by meansof which it may be suspended from any suitable overhead structure. Inconnection with the attachment of suspending elements 11, it will beunderstood, of course, that a suspending member 11 or a pluralitythereof may be suitably attached to the unit 10 whereby it may besuspended in almost any position.

For example, if only two suspending members 11 are used, attached asshown on one edge of unit 10, then the unit will, of course, besuspended with its faces diagonal with respect to the normal ceiling orlike horizontal structural member from which it is suspended. In likemanner the unit may be suspended by suspending members 11 secured at anend thereof, or it may even be suspended by a suspending member suitablysecured thereto at one corner. It is to be understood that the specificmanner or position in which the unit 10 is suspended will in most casesbe immaterial and dictated only by circumstances or expediency, orpossibly by personal preference.

The functional sound absorber hereof is made up of a fiat sheet 12 ofthin metal or the like. This thin metal sheet is, of course, ofdimensions of the developed exterior surface of the unit 10 whereby, asis evident, the flat sheet comprises a body portion of dimensions of thelength of unit 10 by the sum of the width of four sides of the unit orfour times the width of a side of the unit. To such body sheet there areintegrally attached two end pieces of the dimensions of an end of theunit which are positioned such that when the body sheet is folded tosquare form, they may be folded up to constitute end closures thereof.The such end closure portion of the body sheet need not necessarily beintegral therewith,

3 but if desired may be separate sheets or members which can be insertedin the ends of the body portion and secured therein after the bodyportion has been folded into the finished unit form.

To such body sheet 12 there are secured blocks of sound absorbingmaterial of the nature above referred to which are identified by thenumeral 20. Each of these sound absorbing block members 20 is of alength equal to the length of unit 10, of a width equal to the width ofa side of unit 10, and of a height one-half of such width whereby theheight of two blocks 20 is equal to the width of a side of unit 10. Thesound absorbing blocks 20 being of the dimensions just referred to, itfollows that when the body sheet 12 has been folded to its finished orunit form, the two blocks will constitute a volume which is the internalvolume of the body sheet 12 when so formed. These two sound absorbingblocks 23 of a unit are mounted on those portions of the body sheet 12which, when such sheet is folded, comprise opposite surfaces of thefinished unit 10, and with the blocks 20 so mounted and secured bysuitable adhesive the mere procedure of folding the body sheet 12 willresult in the formation of the desired functional sound absorber incomplete form and comprising an outside casing with a filling of soundabsorbing material.

For the purpose of allowing access of impinging sound waves into theinterior of the sound absorber, body sheet 12 is provided with suitableperforations which may comprise small, closely spaced circularperforations, such as 13, or small slots such as are indicated at 130.The size, spacing and number of such perforations for the purpose forwhich they are provided being well known and understood by those skilledin the art of sound absorption, no specific dimensions or numbertherefor will be given, but as an example thereof, reference may be hadto the patent to Norris, No. 1,726,500.

While the body sheet or housing 12 may be secured in any manner desired,as representative of securing means therefor there have been shown smalltongues 14 formed integral with body sheet 12, and registering,

slots 15 whereby, when the body sheet 12 is folded to unit form, thetongues 14 may be entered into slots 15 and bent over to secure the bodyor housing in its final assembled form.

As above referred to, due to the extremely light weight of the units asabove described, it is advantageous, in connection with the shipping andstoring thereof, that in some manner the unit density be increased orvolume occupied by a unit be reduced. In this connection the fabricatedunit, as above described, while still in fiat form, that is, before thesections thereof are folded to constitute the complete unit, admirablylends itself to procedures whereby the volume occupied by a unit may bevery appreciably reduced with consequent advantage in shipping andstoring the material.

The procedure of reducing the volume of the units for the advantagederived therefrom in connection with shipping and storing the same, willbe referred to as packaging of the units. In packaging the units, theyare packaged in pairs, such referring to two of the complete units infiat form, as clearly illustrated in Figure 2 of the drawings. The twounits making up a unit-package are reversed, one with respect to theother, so that the fiber blocks thereon will intermesh, as is clearlyapparent in Figure 4 of the drawings and from which it is apparent thatwhen the respective blocks 20 of the two units are intermeshed thatthere is comprised a solid package which is only one-half the thicknessof the cross sectional dimension of the completed unit 10, as shown inFigure l.

The fiber blocks 20 which constitute the filling of unit 10 arepreferably, as before mentioned, light weight resilient glass fiberblocks or blankets, the fibers of which are bonded at points of contactby suitable adhesive. Such glass wool material is available on themarket having weight of from approximately three-fourths to one poundper cubic foot, but which material is quite resilient and will standconsiderable compression without undue compaction.

For forming a bale of the units for shipment and storage, a suitablenumber of pairs of the units are made into packages, as referred to, andsuch are assembled one on the other to the desired height, whereuponpressure normal to the fiat faces of the packages is applied to compressthe pile of packages to at least the extent of onehalf of the initialheight of the pile. Depending somewhat on the physical properties of theblocks 20 used, the amount of compression which can be accomplished mayvary somewhat, but in general the pile of packages can be compressed toone-third of the original height of the stacked packages, or at least tothe extent of onehalf of such height. After the pile of packages hasbeen compressed, as just referred to, slats 25 may be placed therearoundand bands 26 applied to retain the bale in compressed condition. It, ofcourse, follows that when compressed to one-half the initial height, atleast twice as many units can be stored in any given space, and thattwice the number may be shipped in a car or on a truck. Or, ifcompressed to one-third of the original height that likewise three unitswhen so compressed occupy no more space than would a single unituncompressed. This is of great importance economically in connectionwith the storing and shipping of the units, which is otherwise quiteexpensive due to the very light weight of a unit.

In connection with the specific construction of a unit 10, it may insome cases be desirable to apply a sheet of tissue-like paper 21 to theinterior surface of the casing sheet 12, such sheet being securelyadhered thereto. In adhering tissue sheet 21 to the casing 12, it is tobe understood that it will be necessary to apply the adhesive to thecasing sheet 12 and then to apply the tissue sheet 21 thereto, sincewhile it is desired that the tissue sheet 21 be securely adhered to thecasing sheet, that the portion of the tissue sheet which covers theperforations in the casing sheet should not have glue or adhesivethereon which would tend to or would block the natural porosity of thetissue sheet. It is necessary, to obtain the advantage of theincorporation of such tissue sheet, that the portion of the sheetoverlying the perforations, such as 13, should be porous to air wherebypressure waves impacting thereon may pass therethrough without hindranceother than that resulting from the resistance of the porous tissue sheetto the passage of air therethrough.

The inventions hereof having been described in detail, I claim:

1. An acoustical correction unit comprising a parallelepiped spaceenclosing casing comprised of a shape retaining sheet forming aplurality of the sides of the easing and mounted on the interior surfacethereof blocks of sound absorbing material, such blocks of soundabsorbing material substantially co-extensive with and mounted on theinterior surface of two of said sides of the casing contiguous to athird side thereof, each of such blocks of sound absorbing material of athickness substantially one-half the width of said third side of thecasing.

2. An acoustical correction unit comprising a parallelepiped spaceenclosing casing comprised of a sheet of form-retaining material formingthe walls thereof, the casing sheet perforated for the passage of soundwaves thereinto, an air porous tissue sheet firmly adhered to theinterior surfaces of the enclosing casing and sound absorbing glassfiber blocks of density of about threefourths to one pound per cubicfoot mounted to the tissue sheet on two of the walls of theparallelepiped space enclosing casing contiguous to a third wall thereof, each said block of a thickness substantially one-half of the widthof said third wall and together occupying substantially the entireinterior cavity of the casing.

(References on following page) References Cited in the file of thispatent UNITED STATES PATENTS Donahue July 25, 1944 6 Pare Nov. 22, 1949Olson Mar. 28, 1950 Olson Mar. 28, 1950 Kjaer Dec. 2, 1952 BourgeoisMar. 9, 1954

